Backpack



FIG. 1 is a perspective view of a backpack, showing my new design;

FIG. 2 is a perspective view of the backpack showing the design in an alternate decorated configuration;

FIG. 3 is another perspective view of the backpack shown in FIG. 1;

FIG. 4 is a front view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a left side view thereof;

FIG. 7 is a right side view thereof;

FIG. 8 is a top plan view thereof; and,

FIG. 9 is a bottom plan view thereof.

The broken line showing of the decoration in FIG. 2 is for the purpose of illustrating environmental structure and forms no part of the claimed design. The remaining broken lines depict portions of the backpack that form no part of the claimed design. 

CLAIM The ornamental design for a backpack, as shown and described. 